drivers/misc/ics932s401.c

   1 /*
   2  * A driver for the Integrated Circuits ICS932S401
   3  * Copyright (C) 2008 IBM
   4  *
   5  * Author: Darrick J. Wong <djwong@us.ibm.com>
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation; either version 2 of the License, or
  10  * (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program; if not, write to the Free Software
  19  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  20  */
  21
  22 #include <linux/module.h>
  23 #include <linux/jiffies.h>
  24 #include <linux/i2c.h>
  25 #include <linux/err.h>
  26 #include <linux/mutex.h>
  27 #include <linux/delay.h>
  28 #include <linux/log2.h>
  29
  30 /* Addresses to scan */
  31 static const unsigned short normal_i2c[] = { 0x69, I2C_CLIENT_END };
  32
  33 /* ICS932S401 registers */
  34 #define ICS932S401_REG_CFG2                     0x01
  35 #define         ICS932S401_CFG1_SPREAD          0x01
  36 #define ICS932S401_REG_CFG7                     0x06
  37 #define         ICS932S401_FS_MASK              0x07
  38 #define ICS932S401_REG_VENDOR_REV               0x07
  39 #define         ICS932S401_VENDOR               1
  40 #define         ICS932S401_VENDOR_MASK          0x0F
  41 #define         ICS932S401_REV                  4
  42 #define         ICS932S401_REV_SHIFT            4
  43 #define ICS932S401_REG_DEVICE                   0x09
  44 #define         ICS932S401_DEVICE               11
  45 #define ICS932S401_REG_CTRL                     0x0A
  46 #define         ICS932S401_MN_ENABLED           0x80
  47 #define         ICS932S401_CPU_ALT              0x04
  48 #define         ICS932S401_SRC_ALT              0x08
  49 #define ICS932S401_REG_CPU_M_CTRL               0x0B
  50 #define         ICS932S401_M_MASK               0x3F
  51 #define ICS932S401_REG_CPU_N_CTRL               0x0C
  52 #define ICS932S401_REG_CPU_SPREAD1              0x0D
  53 #define ICS932S401_REG_CPU_SPREAD2              0x0E
  54 #define         ICS932S401_SPREAD_MASK          0x7FFF
  55 #define ICS932S401_REG_SRC_M_CTRL               0x0F
  56 #define ICS932S401_REG_SRC_N_CTRL               0x10
  57 #define ICS932S401_REG_SRC_SPREAD1              0x11
  58 #define ICS932S401_REG_SRC_SPREAD2              0x12
  59 #define ICS932S401_REG_CPU_DIVISOR              0x13
  60 #define         ICS932S401_CPU_DIVISOR_SHIFT    4
  61 #define ICS932S401_REG_PCISRC_DIVISOR           0x14
  62 #define         ICS932S401_SRC_DIVISOR_MASK     0x0F
  63 #define         ICS932S401_PCI_DIVISOR_SHIFT    4
  64
  65 /* Base clock is 14.318MHz */
  66 #define BASE_CLOCK                              14318
  67
  68 #define NUM_REGS                                21
  69 #define NUM_MIRRORED_REGS                       15
  70
  71 static int regs_to_copy[NUM_MIRRORED_REGS] = {
  72         ICS932S401_REG_CFG2,
  73         ICS932S401_REG_CFG7,
  74         ICS932S401_REG_VENDOR_REV,
  75         ICS932S401_REG_DEVICE,
  76         ICS932S401_REG_CTRL,
  77         ICS932S401_REG_CPU_M_CTRL,
  78         ICS932S401_REG_CPU_N_CTRL,
  79         ICS932S401_REG_CPU_SPREAD1,
  80         ICS932S401_REG_CPU_SPREAD2,
  81         ICS932S401_REG_SRC_M_CTRL,
  82         ICS932S401_REG_SRC_N_CTRL,
  83         ICS932S401_REG_SRC_SPREAD1,
  84         ICS932S401_REG_SRC_SPREAD2,
  85         ICS932S401_REG_CPU_DIVISOR,
  86         ICS932S401_REG_PCISRC_DIVISOR,
  87 };
  88
  89 /* How often do we reread sensors values? (In jiffies) */
  90 #define SENSOR_REFRESH_INTERVAL (2 * HZ)
  91
  92 /* How often do we reread sensor limit values? (In jiffies) */
  93 #define LIMIT_REFRESH_INTERVAL  (60 * HZ)
  94
  95 struct ics932s401_data {
  96         struct attribute_group  attrs;
  97         struct mutex            lock;
  98         char                    sensors_valid;
  99         unsigned long           sensors_last_updated;   /* In jiffies */
 100
 101         u8                      regs[NUM_REGS];
 102 };
 103
 104 static int ics932s401_probe(struct i2c_client *client,
 105                          const struct i2c_device_id *id);
 106 static int ics932s401_detect(struct i2c_client *client,
 107                           struct i2c_board_info *info);
 108 static int ics932s401_remove(struct i2c_client *client);
 109
 110 static const struct i2c_device_id ics932s401_id[] = {
 111         { "ics932s401", 0 },
 112         { }
 113 };
 114 MODULE_DEVICE_TABLE(i2c, ics932s401_id);
 115
 116 static struct i2c_driver ics932s401_driver = {
 117         .class          = I2C_CLASS_HWMON,
 118         .driver = {
 119                 .name   = "ics932s401",
 120         },
 121         .probe          = ics932s401_probe,
 122         .remove         = ics932s401_remove,
 123         .id_table       = ics932s401_id,
 124         .detect         = ics932s401_detect,
 125         .address_list   = normal_i2c,
 126 };
 127
 128 static struct ics932s401_data *ics932s401_update_device(struct device *dev)
 129 {
 130         struct i2c_client *client = to_i2c_client(dev);
 131         struct ics932s401_data *data = i2c_get_clientdata(client);
 132         unsigned long local_jiffies = jiffies;
 133         int i, temp;
 134
 135         mutex_lock(&data->lock);
 136         if (time_before(local_jiffies, data->sensors_last_updated +
 137                 SENSOR_REFRESH_INTERVAL)
 138                 && data->sensors_valid)
 139                 goto out;
 140
 141         /*
 142          * Each register must be read as a word and then right shifted 8 bits.
 143          * Not really sure why this is; setting the "byte count programming"
 144          * register to 1 does not fix this problem.
 145          */
 146         for (i = 0; i < NUM_MIRRORED_REGS; i++) {
 147                 temp = i2c_smbus_read_word_data(client, regs_to_copy[i]);
 148                 data->regs[regs_to_copy[i]] = temp >> 8;
 149         }
 150
 151         data->sensors_last_updated = local_jiffies;
 152         data->sensors_valid = 1;
 153
 154 out:
 155         mutex_unlock(&data->lock);
 156         return data;
 157 }
 158
 159 static ssize_t show_spread_enabled(struct device *dev,
 160                                    struct device_attribute *devattr,
 161                                    char *buf)
 162 {
 163         struct ics932s401_data *data = ics932s401_update_device(dev);
 164
 165         if (data->regs[ICS932S401_REG_CFG2] & ICS932S401_CFG1_SPREAD)
 166                 return sprintf(buf, "1\n");
 167
 168         return sprintf(buf, "0\n");
 169 }
 170
 171 /* bit to cpu khz map */
 172 static const int fs_speeds[] = {
 173         266666,
 174         133333,
 175         200000,
 176         166666,
 177         333333,
 178         100000,
 179         400000,
 180         0,
 181 };
 182
 183 /* clock divisor map */
 184 static const int divisors[] = {2, 3, 5, 15, 4, 6, 10, 30, 8, 12, 20, 60, 16,
 185                                24, 40, 120};
 186
 187 /* Calculate CPU frequency from the M/N registers. */
 188 static int calculate_cpu_freq(struct ics932s401_data *data)
 189 {
 190         int m, n, freq;
 191
 192         m = data->regs[ICS932S401_REG_CPU_M_CTRL] & ICS932S401_M_MASK;
 193         n = data->regs[ICS932S401_REG_CPU_N_CTRL];
 194
 195         /* Pull in bits 8 & 9 from the M register */
 196         n |= ((int)data->regs[ICS932S401_REG_CPU_M_CTRL] & 0x80) << 1;
 197         n |= ((int)data->regs[ICS932S401_REG_CPU_M_CTRL] & 0x40) << 3;
 198
 199         freq = BASE_CLOCK * (n + 8) / (m + 2);
 200         freq /= divisors[data->regs[ICS932S401_REG_CPU_DIVISOR] >>
 201                          ICS932S401_CPU_DIVISOR_SHIFT];
 202
 203         return freq;
 204 }
 205
 206 static ssize_t show_cpu_clock(struct device *dev,
 207                               struct device_attribute *devattr,
 208                               char *buf)
 209 {
 210         struct ics932s401_data *data = ics932s401_update_device(dev);
 211
 212         return sprintf(buf, "%d\n", calculate_cpu_freq(data));
 213 }
 214
 215 static ssize_t show_cpu_clock_sel(struct device *dev,
 216                                   struct device_attribute *devattr,
 217                                   char *buf)
 218 {
 219         struct ics932s401_data *data = ics932s401_update_device(dev);
 220         int freq;
 221
 222         if (data->regs[ICS932S401_REG_CTRL] & ICS932S401_MN_ENABLED)
 223                 freq = calculate_cpu_freq(data);
 224         else {
 225                 /* Freq is neatly wrapped up for us */
 226                 int fid = data->regs[ICS932S401_REG_CFG7] & ICS932S401_FS_MASK;
 227                 freq = fs_speeds[fid];
 228                 if (data->regs[ICS932S401_REG_CTRL] & ICS932S401_CPU_ALT) {
 229                         switch (freq) {
 230                         case 166666:
 231                                 freq = 160000;
 232                                 break;
 233                         case 333333:
 234                                 freq = 320000;
 235                                 break;
 236                         }
 237                 }
 238         }
 239
 240         return sprintf(buf, "%d\n", freq);
 241 }
 242
 243 /* Calculate SRC frequency from the M/N registers. */
 244 static int calculate_src_freq(struct ics932s401_data *data)
 245 {
 246         int m, n, freq;
 247
 248         m = data->regs[ICS932S401_REG_SRC_M_CTRL] & ICS932S401_M_MASK;
 249         n = data->regs[ICS932S401_REG_SRC_N_CTRL];
 250
 251         /* Pull in bits 8 & 9 from the M register */
 252         n |= ((int)data->regs[ICS932S401_REG_SRC_M_CTRL] & 0x80) << 1;
 253         n |= ((int)data->regs[ICS932S401_REG_SRC_M_CTRL] & 0x40) << 3;
 254
 255         freq = BASE_CLOCK * (n + 8) / (m + 2);
 256         freq /= divisors[data->regs[ICS932S401_REG_PCISRC_DIVISOR] &
 257                          ICS932S401_SRC_DIVISOR_MASK];
 258
 259         return freq;
 260 }
 261
 262 static ssize_t show_src_clock(struct device *dev,
 263                               struct device_attribute *devattr,
 264                               char *buf)
 265 {
 266         struct ics932s401_data *data = ics932s401_update_device(dev);
 267
 268         return sprintf(buf, "%d\n", calculate_src_freq(data));
 269 }
 270
 271 static ssize_t show_src_clock_sel(struct device *dev,
 272                                   struct device_attribute *devattr,
 273                                   char *buf)
 274 {
 275         struct ics932s401_data *data = ics932s401_update_device(dev);
 276         int freq;
 277
 278         if (data->regs[ICS932S401_REG_CTRL] & ICS932S401_MN_ENABLED)
 279                 freq = calculate_src_freq(data);
 280         else
 281                 /* Freq is neatly wrapped up for us */
 282                 if (data->regs[ICS932S401_REG_CTRL] & ICS932S401_CPU_ALT &&
 283                     data->regs[ICS932S401_REG_CTRL] & ICS932S401_SRC_ALT)
 284                         freq = 96000;
 285                 else
 286                         freq = 100000;
 287
 288         return sprintf(buf, "%d\n", freq);
 289 }
 290
 291 /* Calculate PCI frequency from the SRC M/N registers. */
 292 static int calculate_pci_freq(struct ics932s401_data *data)
 293 {
 294         int m, n, freq;
 295
 296         m = data->regs[ICS932S401_REG_SRC_M_CTRL] & ICS932S401_M_MASK;
 297         n = data->regs[ICS932S401_REG_SRC_N_CTRL];
 298
 299         /* Pull in bits 8 & 9 from the M register */
 300         n |= ((int)data->regs[ICS932S401_REG_SRC_M_CTRL] & 0x80) << 1;
 301         n |= ((int)data->regs[ICS932S401_REG_SRC_M_CTRL] & 0x40) << 3;
 302
 303         freq = BASE_CLOCK * (n + 8) / (m + 2);
 304         freq /= divisors[data->regs[ICS932S401_REG_PCISRC_DIVISOR] >>
 305                          ICS932S401_PCI_DIVISOR_SHIFT];
 306
 307         return freq;
 308 }
 309
 310 static ssize_t show_pci_clock(struct device *dev,
 311                               struct device_attribute *devattr,
 312                               char *buf)
 313 {
 314         struct ics932s401_data *data = ics932s401_update_device(dev);
 315
 316         return sprintf(buf, "%d\n", calculate_pci_freq(data));
 317 }
 318
 319 static ssize_t show_pci_clock_sel(struct device *dev,
 320                                   struct device_attribute *devattr,
 321                                   char *buf)
 322 {
 323         struct ics932s401_data *data = ics932s401_update_device(dev);
 324         int freq;
 325
 326         if (data->regs[ICS932S401_REG_CTRL] & ICS932S401_MN_ENABLED)
 327                 freq = calculate_pci_freq(data);
 328         else
 329                 freq = 33333;
 330
 331         return sprintf(buf, "%d\n", freq);
 332 }
 333
 334 static ssize_t show_value(struct device *dev,
 335                           struct device_attribute *devattr,
 336                           char *buf);
 337
 338 static ssize_t show_spread(struct device *dev,
 339                            struct device_attribute *devattr,
 340                            char *buf);
 341
 342 static DEVICE_ATTR(spread_enabled, S_IRUGO, show_spread_enabled, NULL);
 343 static DEVICE_ATTR(cpu_clock_selection, S_IRUGO, show_cpu_clock_sel, NULL);
 344 static DEVICE_ATTR(cpu_clock, S_IRUGO, show_cpu_clock, NULL);
 345 static DEVICE_ATTR(src_clock_selection, S_IRUGO, show_src_clock_sel, NULL);
 346 static DEVICE_ATTR(src_clock, S_IRUGO, show_src_clock, NULL);
 347 static DEVICE_ATTR(pci_clock_selection, S_IRUGO, show_pci_clock_sel, NULL);
 348 static DEVICE_ATTR(pci_clock, S_IRUGO, show_pci_clock, NULL);
 349 static DEVICE_ATTR(usb_clock, S_IRUGO, show_value, NULL);
 350 static DEVICE_ATTR(ref_clock, S_IRUGO, show_value, NULL);
 351 static DEVICE_ATTR(cpu_spread, S_IRUGO, show_spread, NULL);
 352 static DEVICE_ATTR(src_spread, S_IRUGO, show_spread, NULL);
 353
 354 static struct attribute *ics932s401_attr[] =
 355 {
 356         &dev_attr_spread_enabled.attr,
 357         &dev_attr_cpu_clock_selection.attr,
 358         &dev_attr_cpu_clock.attr,
 359         &dev_attr_src_clock_selection.attr,
 360         &dev_attr_src_clock.attr,
 361         &dev_attr_pci_clock_selection.attr,
 362         &dev_attr_pci_clock.attr,
 363         &dev_attr_usb_clock.attr,
 364         &dev_attr_ref_clock.attr,
 365         &dev_attr_cpu_spread.attr,
 366         &dev_attr_src_spread.attr,
 367         NULL
 368 };
 369
 370 static ssize_t show_value(struct device *dev,
 371                           struct device_attribute *devattr,
 372                           char *buf)
 373 {
 374         int x;
 375
 376         if (devattr == &dev_attr_usb_clock)
 377                 x = 48000;
 378         else if (devattr == &dev_attr_ref_clock)
 379                 x = BASE_CLOCK;
 380         else
 381                 BUG();
 382
 383         return sprintf(buf, "%d\n", x);
 384 }
 385
 386 static ssize_t show_spread(struct device *dev,
 387                            struct device_attribute *devattr,
 388                            char *buf)
 389 {
 390         struct ics932s401_data *data = ics932s401_update_device(dev);
 391         int reg;
 392         unsigned long val;
 393
 394         if (!(data->regs[ICS932S401_REG_CFG2] & ICS932S401_CFG1_SPREAD))
 395                 return sprintf(buf, "0%%\n");
 396
 397         if (devattr == &dev_attr_src_spread)
 398                 reg = ICS932S401_REG_SRC_SPREAD1;
 399         else if (devattr == &dev_attr_cpu_spread)
 400                 reg = ICS932S401_REG_CPU_SPREAD1;
 401         else
 402                 BUG();
 403
 404         val = data->regs[reg] | (data->regs[reg + 1] << 8);
 405         val &= ICS932S401_SPREAD_MASK;
 406
 407         /* Scale 0..2^14 to -0.5. */
 408         val = 500000 * val / 16384;
 409         return sprintf(buf, "-0.%lu%%\n", val);
 410 }
 411
 412 /* Return 0 if detection is successful, -ENODEV otherwise */
 413 static int ics932s401_detect(struct i2c_client *client,
 414                           struct i2c_board_info *info)
 415 {
 416         struct i2c_adapter *adapter = client->adapter;
 417         int vendor, device, revision;
 418
 419         if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
 420                 return -ENODEV;
 421
 422         vendor = i2c_smbus_read_word_data(client, ICS932S401_REG_VENDOR_REV);
 423         vendor >>= 8;
 424         revision = vendor >> ICS932S401_REV_SHIFT;
 425         vendor &= ICS932S401_VENDOR_MASK;
 426         if (vendor != ICS932S401_VENDOR)
 427                 return -ENODEV;
 428
 429         device = i2c_smbus_read_word_data(client, ICS932S401_REG_DEVICE);
 430         device >>= 8;
 431         if (device != ICS932S401_DEVICE)
 432                 return -ENODEV;
 433
 434         if (revision != ICS932S401_REV)
 435                 dev_info(&adapter->dev, "Unknown revision %d\n", revision);
 436
 437         strlcpy(info->type, "ics932s401", I2C_NAME_SIZE);
 438
 439         return 0;
 440 }
 441
 442 static int ics932s401_probe(struct i2c_client *client,
 443                          const struct i2c_device_id *id)
 444 {
 445         struct ics932s401_data *data;
 446         int err;
 447
 448         data = kzalloc(sizeof(struct ics932s401_data), GFP_KERNEL);
 449         if (!data) {
 450                 err = -ENOMEM;
 451                 goto exit;
 452         }
 453
 454         i2c_set_clientdata(client, data);
 455         mutex_init(&data->lock);
 456
 457         dev_info(&client->dev, "%s chip found\n", client->name);
 458
 459         /* Register sysfs hooks */
 460         data->attrs.attrs = ics932s401_attr;
 461         err = sysfs_create_group(&client->dev.kobj, &data->attrs);
 462         if (err)
 463                 goto exit_free;
 464
 465         return 0;
 466
 467 exit_free:
 468         kfree(data);
 469 exit:
 470         return err;
 471 }
 472
 473 static int ics932s401_remove(struct i2c_client *client)
 474 {
 475         struct ics932s401_data *data = i2c_get_clientdata(client);
 476
 477         sysfs_remove_group(&client->dev.kobj, &data->attrs);
 478         kfree(data);
 479         return 0;
 480 }
 481
 482 static int __init ics932s401_init(void)
 483 {
 484         return i2c_add_driver(&ics932s401_driver);
 485 }
 486
 487 static void __exit ics932s401_exit(void)
 488 {
 489         i2c_del_driver(&ics932s401_driver);
 490 }
 491
 492 MODULE_AUTHOR("Darrick J. Wong <djwong@us.ibm.com>");
 493 MODULE_DESCRIPTION("ICS932S401 driver");
 494 MODULE_LICENSE("GPL");
 495
 496 module_init(ics932s401_init);
 497 module_exit(ics932s401_exit);
 498
 499 /* IBM IntelliStation Z30 */
 500 MODULE_ALIAS("dmi:bvnIBM:*:rn9228:*");
 501 MODULE_ALIAS("dmi:bvnIBM:*:rn9232:*");
 502
 503 /* IBM x3650/x3550 */
 504 MODULE_ALIAS("dmi:bvnIBM:*:pnIBMSystemx3650*");
 505 MODULE_ALIAS("dmi:bvnIBM:*:pnIBMSystemx3550*");